It's a great overview of many databases. As the other book "Seven Programming Languages in Seven Weeks", this is a really refreshing series to learn more and expand your horizons, in this one's context, for databases.
I bought and read the physical copy, which only recently in 2024, a month or so ago, I left in the office for motivated readers to pick up. :))
The book was a great introduction to the NoSQL movement in 2015-2106. At the time, I wasn't familiar with CouchBase and Riak. While I saw Riak fragments later in my career, this one prepared me for what would come. 🤬😅
Its chapters are exactly what you'd expect. You learn briefly about a new database, compare it with another you might've already reviewed in the book, and try to get it up and running. That's the whole book. Pretty lean!
Did this book stand the evolution of the industry? I believe, for the most part - no. There's a second edition that I haven't checked out. Maybe that one is better. But at the time of reading it, it was relevant. Since databases evolve, although at a slower rate, enough time has passed for them to lose their relevance.